Partitioning/ segmenting a 2D plane
With your 2D plane selected, enter edit mode with TAB.
Move your mouse along one of the long edges.
Hit CTRL+R.
Roll your mouse wheel until you see the correct number of cuts (in purple).
Click the left mouse button.
Click the right mouse button.


Your plane will now be subdivided into equal parts.

You can now separate them into individual objects by selecting each one in turn (in face select mode) then hitting P then ENTER.